Shown in FIG. 5 is an image projection system 50 comprising: (1) a wire grid polarizer (incoming wire grid polarizer) 56 sandwiched or disposed between a light source 41 and a liquid crystal display (LCD) 42; and (2) another wire grid polarizer (analyzer wire grid polarizer) 55 sandwiched or disposed between an X-Cube 43 and the LCD 42. The wire grid polarizers 55 and 56 can have an array of parallel, elongated strips 54 disposed over a surface of a transparent substrate 11. Each of the strips 54 can include a reflective wire 13 and an absorptive rib 12.
Light 44 from the light source 41 can be polarized at the incoming wire grid polarizer 56. The incoming wire grid polarizer 56 can substantially transmit one polarization (e.g. p-polarized light) and substantially reflect an opposite polarization of light 57 (e.g. s-polarized light). The reflected light 57 from the incoming wire grid polarizer 56 can adversely affect the projected image (e.g. ghosting). Light 47 reflected from the LCD 42, however, can be absorbed by the incoming wire grid polarizer 56 because the absorptive ribs 12 are disposed between the LCD 42 and the reflective wires 13.
Some of the light 44 can pass through the LCD 42 and can be further polarized at the analyzer wire grid polarizer 55. The analyzer wire grid polarizer 55 can substantially transmit one polarization (e.g. p-polarized light) and substantially absorb an opposite polarization (e.g. s-polarized light). The opposite polarization or s-polarized light can be absorbed by the analyzer wire grid polarizer 55 because the absorptive ribs 12 are disposed between the LCD 42 and the reflective wires 13. The light 44 can then reach the X-Cube 43 where light from different directions can combine and be projected. Some of the light reaching the X-Cube 43 can reflect back into the system—back towards the analyzer wire grid polarizer 55. This reflected light 48 from the X-Cube 43 can adversely affect the projected image (e.g. ghosting).
X-Cubes are sometimes called X-Cube prisms or cross dichroic prisms. X-Cubes are commonly used in computer projectors for combining different colors of light into a single image to be projected, X-Cubes are typically made of four right angle prisms, with dichroic coatings, that are cemented together to form a cube.